Fabric trimming and thread laying mechanism for sewing machines



' 2,914,009 FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR sswmcMACHINES Filed Sept. 30. 1955 C. C. SMITH Nov. 24, 1959 10 Sheets-Sheet1 Nov. 24, 1959 c. c. SMITH 2,914,009

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES FiledSept. so. 1955 1o Sheets-Sheet 2 FIG. 2

Nov 24, 1959 c. c. SMITH 2,914,009

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES FiledSept. 30. 1955 10 Sheets-Sheet 3 NOV. 24, 1959 c. c. SMITH ,91 ,0

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES FiledSept. 30. 1955 IOSheetS-Sheet 4 Nov. 24, 195 9 c. c. SMITH FABRICTRIMMING mm mm LAYING MECHANISM FOR szwmc: MACHINES Filed Sept. 30. 195510 Sheets-Sheet 5 AFIG.5

Nov. 24; 1959 c, c. SMITH FABRIC TRIMMING AND THREAD LAYING umcumxsu FORsswmc MACHINES Filed Sept. 50. 1955 10 Sheets-Sheet 6 'FIG.6

FlG.6 A

Nov. 24, 1959 c. GSMITH ,91

FABRIC TRIMMING AND THREAD LAYING MECHANISM FOR SEWING MACHINES FiledSept. 30. 1955 10 Sheets-Sheet 7 2,914,009 FABRIC TRIMMING AND THREADLAYING MECHANISM FOR SEWING mcggrgss Filed Sept. 30. 1955 C. C. SMITHNov. 24, 1959 10 Sheets-Sheet 8 il a i In. u'

C. C. SMITH Nov. 24, 1959 FABRIC TRIMMING AND THREAD LAYING MECHANISMFOR SEWING MACHINES 1o Sheets-Sheet 9 FIG. I?

Filed Sept. 30. 1955 C. C. SMITH Nov. 24, 1959 FABRIC TRIMMING ANDTHREAD LAYING MECHANISM FORv SEWING MACHINES l0 Sheets-Sheet 10 FiledSept. 30. I L955 lllllllllllllllllllllll FIG. l9

I needles.

United States PatentO FABRIC TRIMMING AND THREAD LAYING MECHANISM FORSEWING MACHINES Clarence C." Smith, Chicago, Ill., assignor to UnionSpecial Machine Company, Chicago, 11]., a corporation of IllinoisApplication Septemher 30, 1955, Serial No. 537,673

Claims. (Cl. 112-123) This invention relates to sewing machines of thetype adapted to produce a seam involving a plurality of needle threads,usually three or four, a looper thread cooperating with the needlethread loops on the underface of the work, and a cover thread laidacross the top of the seam and interlocked with the needle threads. Sucha seam is employed to a large extent'in uniting the butted or overlappededges of tubular work formed of knit goods. The invention, therefore, isparticularly concerned with machines of the feed-off-the-arm typeadapted to produce a flat seam of the character mentioned.

Machines adapted to form seams of the type indicated have usually beenprovided with a plurality of needles arranged in a plane transverse tothe line of feed and with a cooperating looper beneath the worksupporting surface for seizing the needle thread loops of all of theAlso such machines have been provided with a pair of cover thread layingfingers movable in coordinated relation above the work supportingsurface to position the cover thread in proper relation to the needlesas the latter are re'ciprocated. In advance of the stitch forming pointa trimmer mechanism has been provided to trim the edges of the workbeing stitched so as to produce a uniform and attractive seam. Suitableconnections have been provided from a drive shaft for operating thevarious stitch forming and trimming mechanisms. Provision has been madealso for lifting and lowering the trimmer mechanism and the cover threadlaying fingers in response to the lifting and lowering of the presserfoot to conform with different thicknesses of work, as in passing overcross seams and the like and also in response to the action of the feeddogs. For this purpose the trimmer mechanism and the thread fingers havebeen mounted on the presser foot or some other part which partakes ofthe up and down movements of the presser foot. The arrangements havebeen such that a substantial part of the weight of the drivingconnections from a drive shaft to the trimmer and fingers has been borneby the presser foot so that a substantial amount of weight has beenrequired to be lifted upon each lifting of the presser foot. Due to theinertia of the relatively heavy parts to be lifted, the maximum speed ofoperation of the machine has necessarily been limited.

It has been a primary object of the present invention to increase thespeed of operation of. a machine of the character indicated, with theproduction of uniform results, by providing novel connections fordriving the trimmer mechanism and the thread laying fingers which arecapable of smooth, efficient and reliable operation at high speed.

One feature of the .novel driving connections is that they render theoperation of the trimmerand thread fingers, during each revolution ofthe main drive shaft, independent of each other so that any retardationof the operation of the trimmer blade will not interfere with the smoothoperation of the thread fingers. Thus if the movable trimmer bladeencounters a cross seam which tends to retard the operation of theblade, through flexing of the driving connections therefor or play inthe parts, the thread laying fingers will continue their normal smoothoperation to produce a uniform seam. This is achieved by the provisionof novel separate connections from the main drive shaft to the drivendevices in question.

Another feature, coordinated with the foregoing, is the construction andarrangement of the indicated driving connections in such a way as toreduce to a minimum the weight of the parts required to be lifted inresponse to the up and down movements of the presser foot.

The preferred embodiment of the invention involves a machine in whichthe thread laying fingers areoperated by a lightweight oscillatorymember connected by suitable linkage with the fingers and arranged to belifted and lowered with the latter in response to the rising and fallingmovements of the presserfoot. The oscillatory member mentioned has asliding connection with a drive member which is mounted on themachine'frame for only rocking or oscillatory movements about a verticalaxis. The drive member is driven frorn the main drive shaft of themachine by an eccentric or the like secured to the latter. On the otherhand, the movable trimmer blade, which cooperates with a ledger, bladeadjustably but fixedly carried by the presserfoot, is operated by anindependent or different connection from the main drive shaft. Thisconnection involves a member mounted on the machine frame for onlyoscillatorymovement about a vertical axis. The movable cutterblade iscarried by the last mentioned member but is arranged for verticalsliding movement in relation thereto; Forthis purpose the blade iscarried by a pin slidable vertically in the oscillatory drivingmemberand is urged downwardly into engagement with the ledger blade by asuitable spring. The arrangement issuch that the presser foot is urgeddownwardly against thework not only by the spring acting upon thepresser bar, in conventional manner, but also by the spring acting onthe trimmer blade. A

A special feature of the new'construction is the provision of a drivingconnection from the conventional needle lever, which operates the.needle bar, to the oscillatory member which carries the movable cutterblade. For this purpose, a rock shaft which carries the needle lever andis operatedthereby is extended slightly at one side of the lever and hassecured thereto an oscillatory arm which is connected by a link with anarm of the above mentioned oscillatory member.

Another special feature, which simplifies the construction and makes itcompact, is the coaxial arrangement of the two oscillatory members whichserve to drive the cover thread laying fingers and the trimmer blade,respectively. Moreover the arrangement is such that the oscillatorymember which'drives the fingers is in the form of a sleeve that receivesoscillatory movements only and forms the lower bearing for the presserbar. The sleeve also provides journals about which the oscillatorymember for driving the trimmer blade may be oscillated.

A further special feature is the provision of a lightweight, spider-likemember mounted on the presser bar for vertical movement'with the presserbar and arranged to partake of the oscillatory movements of the abovementioned sleeve. Lightweight connections are also provided from thespider-like member'to vertically disposed pins or rock shafts journaledin the presser foot and each having secured thereto one of thethreadlaying fingers. The arrangement of the various parts is such that thecover thread carrying finger is given a desirable rapid movement in theregion near the path of the needles and a slower movement in other.portions of its travel. Such rapid movement away from the zone of theneedles provides the desired clearance for the long, hooked finger topass in front of the needles and seize the cover thread and then bringit around to a zone in back of the needles.

Other objects, features, and advantages of the invention will appearfrom the following detailed description of a preferred embodimentthereof in relation to the accompanying drawings, in which:

Fig. 1 is a view, partly in horizontal section and partly in plan, ofthat portion of a machine embodying the invention which is in the regionof the stitch forming mechanism;

Fig. 2 is a view partly in vertical section and partly in elevation ofthe portion of the machine illustrated in Fig. 1;

Fig. 3 is a view similar to Fig. 2 with the vertical section taken alonga different plane;

Fig. 4 is a front elevational view of the head portion of the machinewith the cover plate removed and a portion of the frame broken away;

Fig. 5 is an enlarged detail view, mainly in elevation but partly invertical section, showing the assembly of parts associated with thepresser foot;

Fig. 6 is an elevational view of the presser foot, the lower portion ofthe presser bar, and related mechanism;

Fig. 6A is a detail view in plan of a split collar forming part of theassembly of Fig. 6, the presser bar being shown in section;

Fig. 7 is a plan view of the presser foot and various devices associatedtherewith, with certain parts shown in section at difierent elevations;

Fig. 8 is a view similar to Fig. 7 showing certain moving'parts at adifferent point in their cycle of operation;

Fig. 9 is a view similar to Fig. 7 showing parts in horizontal sectionat a plan beneath that along which Fig. 7 is taken.

Fig. 10 is a view similar to Fig. 9 but with parts in horizontal sectionat a higher elevation than in Fig. 9;

Fig. 11 is a detail view of a spider-like plate member embodied in themechanism;

Fig. 12 is a detail view in elevation of a cover thread carrying finger;

Fig. 13 is a vertical sectional view taken along the line 1313 of Fig.12;

Fig. 14 is a view of the cover thread carrying finger as seen from theright in Fig. 12;

Fig. 15 is a plan view of a cover thread seizing hook forming a secondfinger of the cover thread laying mechanism;

Fig. 16 is a view ofthe finger shown in Fig. 15 as seen from the left ofthe latter;

Fig. 17 is an exploded perspective view showing the mounting andoperating means for a movable cutter blade;

Fig. 18 is a vertical sectional view through the presser foot;

Fig. 19 is a bottom plan view of the presser foot; and

Fig. 20 is a plan view of a throat plate carried by the work supportingmember of the machine.

The invention has been illustrated as applied to a feed-off-the-armmachine of the general type disclosed in the patent to Christensen etal. No. 1,741,095, granted December 24, 1929. This patent discloses thegeneral form of the frame of the machine and the arrangement of suitableoperating mechanism. Modifications of the mechanism of said Christensenet a1. patent which are incorporated in-the illustrative machine aredisclosed in my copending application Serial No. 208,400, filed January29, 1951, now Patent No. 2,729,176. The present invention is directed tovarious important changes in the mechanism disclosed in said copendingapplication. Accordingly the description will be confined largely to thefeatures of the machine which incorporate those changes.

Referring now to the drawings, the machine comprises a frame having amain horizontally extending top portion 10 from which there projectslaterally a head 11 in which the needle bar is reciprocated and in whichvarious other mechanism is mounted. At the right end of the frame (Fig.l) which is not shown in the drawings, there is formed a downwardlyextending arm from which projects horizontally a work carrying arm 12extending at an angle to the vertical plane through the axis of portion10 of the frame. The free end of the arm 12 extends beneath the head 11of the frame. Suitably journaled in the portion 10 of the frame is amain rotary drive shaft 13, which carries at its outer end a drivingpulley 14 through which power is supplied to the machine. Shaft 13 has acrank portion 15 which cooperates with a strap 16 of a short downwardlyextending pitman. Needle bearings 17 are preferably provided between thecrank 15 and strap 16. The lower end of the pitman is pivotallyconnected with an arm 18 of a needle lever having a hub portion 19secured to a rock shaft 20. A forwardly extending arm 21 of the needlelever is connected by a link 22 with a block 23 secured to a needle bar24 which is arranged for vertical reciprocation in suitable bearingsleeves carried by the head 11. It will be understood that link 22 ispivotally connected with the arm 21 and the block 23. The needle bar 24carries at its lower end a needle clamp 25 (Fig. 6) adapted to retain aplurality of needles 26. In the illustrative machine four such needlesare provided. These are disposed in a vertical plane transverse to theaxis of the arm 12 and are arranged for reciprocation from a point abovesaid arm to a point at which the thread carrying eyes of the needles arebeneath the work supporting surface of the arm.

It should be understood that in accordance with the above mentionedcopending application the arm 12 carries a looper which cooperates withthe needles in stitch formation and it also carries differential feedmechanism. The looper and four-motion feed dogs are driven from theshaft 13.

A presser bar 27 is mounted for vertical movement in the head 11. Itsupper end is slidable in a bearing sleeve 28 (Fig. 2) while its lowerend is slidable in a sleeve 29 (Figs. 5, 6, and 10) arranged for onlyoscillatory movement in relation to the frame. Sleeve 29 is mounted foroscillation in a bearing sleeve 30 extending through and suitablysecured within the bottom wall of the head 11. To the lower end of thepresser bar 27 there is secured a presser foot structure designatedgenerally by the reference number 31. The presser foot assemblycomprises a main support 32 having an opening which receives the lowerend of the presser bar and support 32 is secured to the presser bar bymeans of a set screw 33 (Figs. 5 and 6). The presser foot has a solepiece formed with toe portions 32a and 32b extending in the directionfrom which the work is fed, these toe portions being spaced to permitthe passage therebetween of the upturned edges of the work. Flat springmembers 320 are carried by the sole piece for yielding engagement withthe work. To prevent turning of the presser foot and to confine itsmovement to up and down vertical movements, there is provided a pair ofguide members secured to the frame and arranged to cooperate withportions of the main support 32 of the presser foot structure. Thus, asshown in Fig. 5, an arm 34 cooperating with the presser foot has itsupper end 34a bent laterally and secured by a screw 35 to the bottom ofhead 11 of the frame. Similarly a guide finger 36 cooperating with theopposite side of the presser foot structure is secured by screws 37 tothe bottom of the head 11. Turning of the presser foot is also resistedby means carried by the presser bar 27. Thus, as best shown in Fig. 4, amember 38 secured to the presser bar has a forked end cooperating withand slidable vertically along flattened surfaces of a pin or stud 39extending downwardly from the top of the head 11. A flat spring 40(Figs. 2 and 3) is arranged to urge the presser bar downwardly to engagethe presser foot yieldingly with the work. Spring 40 carries at one enda cap 41 arranged to fit over an upwardly extending pin or stud springcarriesa cap 42 which fits over a reduced portion at the upper end ofthe presser bar. In its central region 'the spring 40 is apertured toreceive a screw stud 43 having a knurled nut 43a which may be turned toadjust the tension of the spring.

Conventional means are provided for lifting the presser bar and presserfoot to facilitate the introduction and removal of work. For thispurpose an arm'44 extending rearwardly from a rock shaft journaled inthe frame 10 is adapted for connection by a chain or the like to a foottreadle or knee press. A spring (not shown) nor- "mally urges the arm 44and shaft 45 in a clockwise direction' (Figs. 2 and 3). When these partsare rocked in a counterclockwise direction an upwardly extending arm 46secured to the'shaft 45 is rocked rearwardly. To the upper end of arm 46there'is pivotally connected a link 47 having its forward end pivotallyconnected-with arm 48 secured to a rock shaft 49.] The latter carries ahorizontally extending finger 50 disposed slightly below a finger '51 ofthe member 38 secured to the presserbar. It will be seen thatcounterclockwise movement of the arms 46 and 48 will thus bringaboutlifting of the presser bar and presser foot assembly.

Mounted on the main support 32 of the presser foot is a pair of coverthread laying fingers. One of these is a thread carrying finger 52whichi's shown indetail in Figs.

12, l3, and '14. It comprises a finger 52;: having a thread receivingeye and spaced therefrom a finger 52b of fishtail 'form. Finger 52 issecured to a stud or rockshaft 53 jourslightly in rear thereof as thefinger reaches the position shownin' Fig. .8. In the meantime the finger52 shifts in properly timed relation betweenithe two positions shown inthese figures. V

The mechanism for oscillating the fingers 52 and 55 'aboutthei'rsupporting rock shafts comprises'a spider-like "plate member 58 having acollar 59 surrounding the presser bar 27 and arranged for freeoscillationabout the presser bar and for axial movement with the presserbar. An arm 60 secured to the upper end of the rock shaft 53 ispivotally connected by means of a pin 61 with a link 62, the oppositeend of which is pivotally connected by means of a pin 63 with the member58. Link'62, as best shown in Fig. 6, is bifurcated at its two ends tostraddle the arm 60 and the member 58. Pin-63 may be-secured againstaxial movement in the plate 68 bymeans of set screw 64. 1 Similar meansmay be provided to retain the "pin 61in proper axialrelation to the arm60. The means for oscillatingthe hooked finger55 comprises an arm 65secured to the upper end of the rock-shaft 56 and carrying at its outerend a pin 66 for pivotal connection with a link 67'whichis, in turn,pivotally connected by means of a pin 68 with themernber 58. Link 67 isforked at its ends to straddle the arm 65 and the member 58 and thepivot pins are retained in the same manner as pin 63.

"The connections between the member 58 and the two fingers are such thatas the member 58 is moved in a clockwise direction finger 52 will berocked in a counterclockwise direction, while finger 55 willbe' rockedclockwise, and vice-versa. Also the positioning of the various centersof the links and arms conne'cting the two fingers with the member 58 issuch that a proper timing in-the operation of the two fingers is broughtabout. The finger 52is rocked outwardly away from the position showninFig'. 8 at a rapid rate to provide clearance-forthe'in- Ward movementof the finger 55. The latter, "it will be its understood, rides over thethread extending from the eye'- let 52a to the outer needle and then onreverse movement serves to draw this thread across the front of theneedles and to a position slightly in rear of the same.

I For rocking the member 58 while at the same time permitting freevertical movement of the latter, thesleeve 29' above described carriesat its lower end a collar 69 (Figs 6 and 10) having a radially extendingarm 70 and a downwardly projecting finger 71. The latter'fits into anotch or groove in the outer edge of the member 58 so that oscillatorymovements of the sleeve 29 are imparted to'the member 58, but the latteris free to move vertically relative to the sleeve. In so doing, thewalls of the notch or groove slide along the finger 71. It will beunderstood that the connections described above for operating-thefingers 52 and 53 are such that all of the parts, including member 58,will rise and fall with the presser foot. However, the main drivingmember, i.e. sleeve'29, does not rise and fall with the presser foot.

"Qscillatory movements are imparted to the sleeve 29 by connectionsincluding a'split collar 72 clamped upon the sleeve. This collar has anupwardly extending arm 73; (Figs. 1,6 and6A) which carries a ball pin74cooperating with a strap at one endof a pitman 75. Another strap at theopposite end of said pitman cooperates with a spherical eccentric 76secured to the drive shaft 13. Thus upon each revolution of the mainshaft the sleeve 29 will be oscillated through a suitable arc to drivethe thread fingers 52 and 55 through a complete cycle.

Cooperating with the stitch forming devices, to insure proper formationof the stitches,-there is provided a plurality'of sets of stitchfingers. One of these is carried by the throat plate and the other iscarried by the presser foot. Referring to Fig. 20 there is showna throatplate 77 which is suitably secured to the top of the work supporting arm12. A small plate 78 carrying three stitch fingers 79 is attached to thetop ofthe throat plate and fitted'into a depression therein so that thetop of the plate 78 is flush with'the top of thethroat plate. In themachine illustrated, the fourneedles are arranged to pass through therectangular opening 77a into which the fingers 79 extend. The two innerneedles pass through the two slots, which form the three stitch fingers,at points adjacent the inner ends of these slots, while the outerneedles pass through the spaces adjacent the outer edges of the plate78. In Figs. 18 and 19 there is shown a stitch finger blade 80 which isfitted into a recess in the bottom of the presser foot and securedthereto by means of the screws shown. The blade is slotted to form threefingers 81 which extend rearwardly in the direction of feed, one of thefingers being longer than the others. It will be understood that thefour needles pass through the spaces between the fingers and at thesides of the outermost fingers. The longer finger as shown, for example,in Fig. 9, is positioned adjacent the needle from which the cover threadis drawn across the bank of needles and it assists in retaining thethreads in proper position until each stitch is completely formed.

The presser foot is preferably also provided with a small sp'ringpressed plunger 82 having a shank fitted into'a recess in the body 32 ofthe presser foot. Plunger 82, which is urged downwardly by a spring 83toward the throat plate, has its bottom flattened and extended into therectangular form shown in Fig. 19. It is in the path of the line ofstitching formed by the stitch forming devices and serves to retain thethread chain when the machine is chaining outbetween work pieces.

" Means are provided for trimming the free edges of the work in advanceof the stitch forming point. For this purpose a ledger blade 84ismounted in a suitable recess adjacent the bottom of the presser foot(see Fig. 8). The ledger blade is clamped in place by apart 85 at thebottom 'of the presser foot which is tightened against the blade bymeans of a screw 86. Cooperating with the ledger blade is a-movablecutter blade 87. This has a bevelled forward edge 88"inclined slightlytothe path of travel of the edges of thework. A finger 89 extendingoutwardly from 2 the edge 88 overlies the ledger blade and insurescorrect cooperation of the cutting edges of the two blades. The blade 87is retained in grooves provided in downwardly extending legs of achannel member 90 (Fig. 6). A clamping screw 91 serves to lock the bladewhen properly adjusted. Between the top of blade 87 and the top of thechannel member 90 is a thin metal insert 92 into which a screw 93 isthreaded to further retain the parts in set position. Channel member 90is secured to the lower end of arod 94 (Figs. 5, 6, 8, and 17). This rodis slidably received by lugs 95 and 96 projecting from the lower andupper edges of an arm 98 which extends downwardly at the outer end of abent arm 97. A collar 99, secured by a set screw 100 to the rod 94, hasa finger 101 arranged to slide in a slot or channel 102 in the arm 98.This serves to prevent rotation of the rod 94 and of the blade 87. Aspring 103 acting at one end against the under face of the lug 96 and atits other end against the top of the collar 99 serves to urge the rod 94and blade 87 downwardly to retain the movable blade in engagement withthe ledger blade. As will be apparent, the spring 103 adds slightly tothe downward pressure applied to the presser foot. The bent arm 97extends horizontally from a collar 104 mounted for oscillation upon thesleeve 29. A yoke 105 connects the collar 104 with an aligned collar 106which is also mounted for oscillation about the sleeve 29. Extendingradially from collar 106 is an arm 107 having its outer end upturned andarranged to carry a ball pin 108. This pin cooperates with a sphericalstrap 109 at one end of an extensible link 110 (Fig. 3). At its oppositeend this link has a strap 111 cooperating with a ball pin 112 extendinglaterally from an arm 113 secured to the rock shaft 20. The latter, ashas been explained, is rocked with the needle lever by the connectionsdescribed from the main drive shaft 13. It will be apparent from theforegoing that the main operating mechanism for the movable cutter bladeis mounted for only oscillatory movement on the frame of the machine andnone of its weight is borne by the presser foot. The latter simplycarries the weight of the rod 94 and the blade 87 together with itsholder.

A curved plate 114 is mounted on the top of the forwardly extendingportion of the presser foot. This plate, which has an car by which it isattached to the presser foot by means of a screw 115, extends across thetops of the cutter blades at an angle to the line of feed and serves todeflect to the side of the presser foot the trimmings produced by theblades.

It will be seen from the foregoing that the operating means for thethread fingers 52 and 55 comprises the sleeve 29 which is mounted foroscillation only about the presser bar while the movable cutter blade ofthe trimmer is driven from a member 105, etc. mounted for oscillationonly on the sleeve 29. The sleeve 29 and member 105 are driven byseparate connections from the shaft 13 to oscillate the fingers andcutter blade in properly timed relation and through a complete cycle andto an appropriate extent upon each revolution of the main shaft.Relatively lightweight connections are provided from the sleeve 29 andmember 105 to the thread fingers and trimmer, respectively, so as toreduce to a minimum the inertia of the presser foot. The arrangement issuch that the machine may be driven at higher speeds than heretoforepossible, with the production of a uniform seam.

While an illustrative embodiment of the invention has been disclosed inconsiderable detail, it will be understood that various changes may bemade in the construction and arrangement of the several parts within thescope of the appended claims.

What is claimed is: p

1. In a sewing machine having a frame provided with a horizontallyextending top portion below which is provided a work supporting surface,a main rotary drive shaft journaled in said top portion of the frame forrotary movement'constantly' in the same direction, a plurality ofneedles mounted for reciprocation through said surface, a loopercooperating with the needles belowsaid surface, cover thread layingfingers cooperating with said needles above said surface and trimmermechanism for trimming the edges of the work in advance of said needles,the combination which comprises separate connections extending forwardlyand downwardly from said shaft at spaced points thereon for driving saidfingers and said trimmer mechanism, respectively, through a completecycle upon each revolution of said shaft, the downwardly extendingportions of said separate connections having members which oscillateabout a common axis.

2. In a sewing machine having a frame provided with a work supportingsurface, a main drive shaft journaled in said frame for rotary movementconstantly in the same direction, a plurality of needles mounted forreciprocation through said surface, a looper cooperating with theneedles below said surface, cover thread laying fingers cooperating withsaid needles above said surface and trimmer mechanism for trimming theedges of the work in advance of said needles, the combination whichcomprises connections from said shaft for reciprocating said needles,said connections including a needle lever and a rock shaft to which'saidlever is secured and which is thus driven by said lever, a membermounted for only oscillatory movement on said frame and driven from saidrock shaft for operating said trimmer mechanism, and connections fromsaid drive shaftindependent of said first mentioned connections fordriving said fingers.

3. Ina sewing machine having a frame provided with a work supportingsurface, a main drive shaft journaled in said frame for rotary movementconstantly in the same direction, a plurality of needles mounted forreciprocation through said surface, a looper cooperating with theneedles below said surface, cover thread laying fingers cooperating withsaid needles above said surface and trimmer mechanism for trimming theedges of the work in advance of said needles, said fingers andsaid-trimmer mechanism being arranged to rise and fall in response tovariations in thickness of the Work, the combination which comprises aplurality of oscillatory members mounted on said frame for oscillatorymovement only, lightweight connections from one of said membersincluding a part slidable thereon and driven thereby for operating saidtrimmer mechanism, lightweight connections from the other of saidmembers including a part slidable rectilinearly thereon and driventhereby for operating said fingers, a pair of eccentrics carried by saidshaft and connections from each of said eccentrics to a related one ofsaid members for oscillating the latter.

4. In a sewing machine having a frame provided with a work supportingsurface, a main drive shaft journaled in said framefor rotary movementconstantly in the same direction, a plurality of needles mounted forreciprocation through said surface, a looper cooperating with theneedles below said surface, cover thread laying fingers cooperating withsaid needles above said surface and trimmer mechanism fortrimming theedges of the work in advance of said needles, said fingers and saidtrimmer mechanism being arranged to rise and fall in response tovariations in thickness of the work, the combination which comprises aplurality of oscillatory members mounted on said frame for oscillatorymovement only about a common axis, lightweight connections from one ofsaid members including a part slidable thereon and driven thereby foroperating said trimmer mechanism, lightweight connections from the otherof said members including apart slidable rectilinearly thereon anddriven thereby for operating said fingers, a pair of eccentrics carriedby said shaft and connections from each of said eccentrics to a relatedone of said members for oscillating the-latter.

5. A sewing machine having a frame provided with a work supportingsurface and a head extending over said surface, a needle bar mounted forreciprocation in said head and carrying a plurality of needles forreciprocation therewith, a pressure bar mounted vertically for axialmovement in said head, a presser foot secured to the lower end of saidpresser bar, spring means urging said presser bar downwardly to urgesaid presser foot yieldingly against said work supporting surface, alooper beneath said surface and a pair of thread laying fingers abovesaid surface cooperating with saidneedles to form a seam embodying acover thread, trimmer mechanism for trimming the edges of the work inadvance of the stitch forming point, said thread laying fingers and saidtrimmer mechanism being arranged to partake of the up and down movementsof the presser foot, a main drive shaft in said frame for rotarymovement constantly in the same direction, and connections from saidshaft for operating said needle bar, said looper, said thread layingfingers and said trimmer mechanism, said connections to said fingers andtrimmer mechanism, respectively, each comprising a separate cam on saidshaft and a separate oscillatory member mounted on said frame foroscillation about the axis of said presser bar.

6. A sewing machine having a frame provided with a work supportingsurface and a head extending over-said surface, a needle bar mounted forreciprocation in said head and carrying a plurality of needles forreciprocation therewith, a presser bar mounted vertically for axialmovement in said head, a presser foot secured to the lower end of saidpresser bar, spring means urging said presser bar downwardly to urgesaid presser foot yieldingly against said work supporting surface, alooper beneath said surface and a pair of thread laying fingers abovesaid surface cooperating with said needles to form a seam embodying acover thread, trimmer mechanism for trimming the edges of the work inadvance of the stitch forming point, said thread laying fingers and saidtrimmer mechanism being arranged to partake of the up and down movementsof the presser foot, a main drive shaft in said frame, and connectionsfrom said shaft for operating said needle bar, said looper, said threadlaying fingers and said trimmer mechanism, said connections to saidfingers and trimmer mechanism, respectively, each comprising a separateoscillatory member mounted on said frame for oscillation about the axisof said presser bar, said oscillatory members being retained against upand down movement with the presser foot and having a bodily slidingdrive connection with parts carried by said fingers and trimmermechanism.

7. A sewing machine having a frame provided with a work supportingsurface and a head extending over said surface, a needle bar mounted forreciprocation in said head and carrying a plurality of needles forreciprocation therewith, a presser bar mounted vertically for axialmovement in said head, a presser foot secured to the lower end of saidpresser bar, spring means urging said presser bar downwardly to urgesaid presser foot yieldingly against said work supporting surface, alooper beneath said surface and a pair of thread laying fingers abovesaid surface cooperating with said needles to form a seam embodying acover thread, trimmer mechanism for trimming the edges of the work inadvance of the stitch forming point, said thread laying fingers and saidtrimmer mechanism being arranged to partake of the up and down movementsof the presser foot, a main drive shaft in said frame, and connectionsfrom said shaft for operating said needle bar, said looper, said threadlaying fingers and said trimmer mechanism, said connections to saidfingers and trimmer mechanism, respectively, each comprising a separateoscillatory member mounted on said frame for oscillation about the axisof said presser bar, and said connections to said fingers including aplate oscillatable about the axis of said presser bar and having abodily sliding drive connection with-the related 0s the lower end ofsaid presser bar, spring means urging said presser bar downwardly tourge said presser foot yieldingly against said work supporting surface,a looper beneath said surface and a pair of thread laying fingers abovesaid surface cooperating with said needles to form a seam embodying acover thread, trimmer mechanism for trimming the edges of the work inadvance of the stitch forming point, said thread laying fingers and saidtrimmer mechanism being arranged to partake of the up and down movementsof the presser foot, a main drive shaft in said frame, and connectionsfrom said shaft for operating said needle bar, said looper, said threadlaying fingers and said trimmer mechanism, said connections to saidfingers and trimmer mechanism, respectively, each comprising a separateoscillatory member mounted on said frame for oscillation about the axisof said presser bar, and said connections to said fingers including aplate oscillatable about said presser bar and having a sliding driveconnection with the related oscillatable member, said last mentionedconnections also including links pivotally attached to said plate atopposite sides of the presser bar.

9. A sewing machine having a frame provided with a work supportingsurface and a head extending over said surface, a needle bar mounted forreciprocation in said head and carrying a plurality of needles forreciprocation therewith, a presser bar mounted vertically for axialmovement in said head, a presser foot secured to the lower end of saidpresser bar, spring means urging said presser bar downwardly to urgesaid presser foot yieldingly against said work supporting surface, alooper be neath said surface and a pair of thread laying fingers abovesaid surface cooperating with said needles to form a seam embodying acover thread, trimmer mechanism for trimming the edges of the work inadvance of the stitch forming point, said thread laying fingers and saidtrimmer mechanism being arranged to partake of the up and down movementsof the presser foot, a main drive shaft in said frame, and connectionsfrom said shaft for operating said needle bar, said looper, said threadlaying fingers and said trimmer mechanism, said connections to saidfingers comprising a sleeve surrounding said presser bar and arrangedfor only oscillatory movement about the axis of said presser bar, aplate having a bodily sliding connection with said sleeve arranged foroscillation with the latter and for axial movement in relation thereto,and linkage connecting said plate with said fingers.

10. A sewing machine having a frame provided with a work supportingsurface and a head extending over said surface, a needle bar mounted forreciprocation in said head and carrying a plurality of needles forreciprocation therewith, a presser bar mounted vertically for axialmovement in said head, a presser foot secured to the lower end of saidpresser bar, spring means urging said presser bar downwardly to urgesaid presser foot yieldingly against said work supporting surface, alooper beneath said surface and a pair of thread laying fingers abovesaid surface cooperating with said needles to form a seam embodying acover thread, trimmer mechanism for trimming the edges of the work inadvance of the stitch forming point, said thread laying fingers and saidtrimmer mechanism being arranged to partake of the up and down movementsof the presser foot, a main drive shaft in said frame, and connectionsfrom said shaft for operating said needle bar, said looper, said threadlaying fingers and said trimmer mechanis m, said connections to saidfingers comprising a sleeve surrounding said presser bar and arrangedfor only oscillatory movement about the axis of said presser bar, aplate having a sliding connection with said sleeve arranged foroscillation with the latter and for axial movement in relation thereto,and linkage connecting said plate with said fingers, said connections tosaid trimmer mechanism comprising a member mounted on said sleeve foronly oscillatory movement about the axis of said presser bar, saidtrimmer mechanism having a part slidable vertically in relation to saidmember and arranged tobe driven by the latter.

References Cited in the file of this patent UNITED STATES PATENTS

